Data regarding Asian patients with mycosis fungoides (MF) are limited.

We aimed to investigate the clinical profile and long-term outcomes of patients with MF in Korea.

A retrospective review of 223 patients with MF who were followed up for more than 6 months or died of MF within 6 months of diagnosis was performed.

Approximately 96.4% and 3.6% of the patients had an early stage and advanced stage, respectively. The mean age at diagnosis was 44.8 years. The mean duration of symptoms before diagnosis was 47.0 months. Various subtypes were noted, including mycosis fungoides palmaris et plantaris (21.5%), folliculotropic (8.5%), pityriasis lichenoides-like (6.7%), ichthyosiform (4.0%), lichenoid purpura-like (2.7%), and hypopigmented (2.2%) MF. Juvenile patients accounted for 16.6%. The higher the skin T stage, the poorer the response to treatment. The 10-year overall survival was 96.8% in early-stage patients and 25.0% in advanced-stage patients. General prognosis was favorable, while recurrence and subtype switching were seen in 29.4% and 2.7% of patients, respectively.

Our patients may not represent all Korean patients with MF.

MF in Korea has a high proportion of variants, a younger age at onset, and favorable prognosis. A high index of suspicion and skin biopsy are needed for early diagnosis.